Abstract

Background: Ecosystems above the natural treeline are considered alpine ecosystems. However, geomorphology and microclimate are important components in defining alpine ecosystems. Species composition and its underlying climatic factors in high-altitude alpine ecosystem (HAAE) and high-latitude alpine ecosystems (HLAE) remain poorly studied. These ecosystems are characterized by low temperature, limited precipitation and high sensitivity to climate change. They also exhibit variation in environmental factors such as solar radiation and topography. This study aims to explore the species composition and climatic drivers of these two distinct alpine ecosystems. Data were collected from 40 plots of 100 square meters in each ecosystem, and non-metric multidimensional scaling and canonical correspondence analysis were employed to assess species composition and identify key climatic factors influencing these patterns. Results: Our results revealed notable differences between the species present in HAAE and those in HLAE. HAAE species were more sensitive to precipitation, whereas HLAE species responded more strongly to temperature. Specifically, growing season length and mean annual precipitation were critical determinants of species composition in HAAE, while mean temperature of the warmest quarter and mean annual temperature were more influential in HLAE. Conclusions: This study provides important insights into the species compositional differences between HAAE and HLAE and highlights the distinct climate drivers shaping plant species composition in these ecosystems. It suggests the need to incorporate other biotic and edaphic factors that may be important in explaining species compositional differences in these unique ecosystems.